where in vaccum should my gauge read at idle
Mar 14, 2006, 09:58 AM
#5
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wierdest thing. my gauge reads 15 at idle, but the positive boost is correct. the gauge shows 21, and the datalog showed that is correct.
can't figure out why it's only -15 at idle.
gauge is an autometer.
can't figure out why it's only -15 at idle.
gauge is an autometer.
Mar 14, 2006, 10:00 AM
#7
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My Autometer reads -15 as well...
Originally Posted by DahakaJR
wierdest thing. my gauge reads 15 at idle, but the positive boost is correct. the gauge shows 21, and the datalog showed that is correct.
can't figure out why it's only -15 at idle.
gauge is an autometer.
can't figure out why it's only -15 at idle.
gauge is an autometer.
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Mar 14, 2006, 12:06 PM
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it's cams like that guy said.
sometimes the cam makes the afr lean or rich. and when that happens, ecu compensates it by breathing in more idle air or dump in more fuel.
You'll see the vac go up and down as the afr changes on your wideband.
That's what I've noticed.
if I'm wrong, if you boost normal, you shouldn't really worry about vac, unless it's near the 0 at idle.
sometimes the cam makes the afr lean or rich. and when that happens, ecu compensates it by breathing in more idle air or dump in more fuel.
You'll see the vac go up and down as the afr changes on your wideband.
That's what I've noticed.
if I'm wrong, if you boost normal, you shouldn't really worry about vac, unless it's near the 0 at idle.
Mar 14, 2006, 12:48 PM
#14
Pulled from the shop manual
MANIFOLD VACUUM CHECK M1111002700387
1. Before inspection, check that the engine oil, starter and
battery are normal. Also, set the vehicle to the following
conditions:
• Engine coolant temperature: 80 − 95°C (176 − 203°F)
• Lights, and all accessories: OFF
• Transaxle: Neutral
2. Connect an engine tachometer.
3. Attach a tee-fitting joint to the vacuum hose between the fuel
pressure solenoid and the intake manifold plenum, and
connect a vacuum gauge.
4. Start the engine and check that idle speed is within
specification. Then check the vacuum gauge reading.
Idle speed: 850 ± 100 r/min
Minimum limit: 51 kPa (15 in Hg)
With cams your vaccum is going to read lower. Here in UT we se around 12-13is with cams.
Ben
MANIFOLD VACUUM CHECK M1111002700387
1. Before inspection, check that the engine oil, starter and
battery are normal. Also, set the vehicle to the following
conditions:
• Engine coolant temperature: 80 − 95°C (176 − 203°F)
• Lights, and all accessories: OFF
• Transaxle: Neutral
2. Connect an engine tachometer.
3. Attach a tee-fitting joint to the vacuum hose between the fuel
pressure solenoid and the intake manifold plenum, and
connect a vacuum gauge.
4. Start the engine and check that idle speed is within
specification. Then check the vacuum gauge reading.
Idle speed: 850 ± 100 r/min
Minimum limit: 51 kPa (15 in Hg)
With cams your vaccum is going to read lower. Here in UT we se around 12-13is with cams.
Ben
